1. Field of the Invention
The present invention relates to a media library system having a storehouse for storing a large number of recording media such as optical disks, magnetic disks, magnetic tapes, etc., which carries out the exchange of the recording media and the data access to the recording media automatically.
2. Description of the Background Art
The optical disk device is a storage device for exchangeably storing optical disk media, where each optical disk medium is either a type of 90 mm diameter having several hundred MB recording capacity or a type of 130 mm diameter having approximately 1 GB recording capacity, such that unlimited amount of recording capacity can be realized in principle by the exchange of the optical disk media.
In recent years, there has been a development of an optical disk library system which realizes the recording capacity of 1 TB level by carrying out the exchange of the optical disk media automatically, by taking an advantage of such an optical disk device. This optical disk library system has a schematic configuration as shown in FIG. 1, in which a standard type cartridge 1 containing one optical disk medium is mounted onto a disk drive 2 to carry out data read/write with respect to the optical disk medium contained in the cartridge 1, and an arbitrary cartridge 1 stored in a storage cell 3a of a storehouse 3 can be exchanged with the cartridge 1 in the disk drive 2 by being conveyed by a robotic hand 4 of an automatic disk handling mechanism.
Normally, in a case of exchanging the cartridges 1, as shown in FIG. 1, the cartridge 1 taken out from the disk drive 2 is conveyed over to the prescribed storage cell 3a of the storehouse 3 by the robotic hand 4 as indicated by an arrow 1, and then the robotic hand 4 is moved over to the storage cell 3a of a next cartridge 1 as indicated by an arrow 2, and finally this next cartridge 1 is conveyed over to the disk drive 2 as indicated by an arrow 3.
Consequently, in order to improve the access performance in this optical disk library system, it is important to shorten a distance between the disk drive 2 and the storage cell 3a of the storehouse 3, and it is preferable to position the cartridges 1 containing the optical disk media with high utilization frequencies nearby the disk drive 2.
However, in the conventional optical disk library system of FIG. 1, a storing position of each cartridge 1 is fixedly set at a time of installing each cartridge 1 on the optical disk library system, so that when the cartridge 1 containing the optical disk medium with a high utilization frequency is stored at a position distanced from the disk drive 2, a long access time is required every time the exchange of the cartridges 1 is carried out with respect to that optical disk medium, and this in turn can lead to the lowering of the overall access performance of the optical disk library system.